Could omega-3 fatty acids a therapeutic treatment of the immune-metabolic consequence of intermittent hypoxia in obstructive sleep apnea?

Obesity and Obstructive sleep Apnea (OSA) seems to bi-directional; obesity itself increases the risk of OSA, but on the other hand, OSA may also predispose the individuals to weight gain, both obesity and OSA share a common immune-metabolic link state which have a synergistic effect on the activation of inflammation, insulin resistance and dyslipidemia, and cardiovascular disease. The Immune-metabolic role of omega-3 fatty acids Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA), which capable of modulating both metabolic and immune process, which may decrease pro-inflammatory cytokines, insulin resistance, and dyslipidemia. To date, no study in humans suffering from OSA and omega-3 fatty acids has been performed. Hence, the objective of this review aimed to discussing the link between immune-metabolic consequences related to intermittent hypoxia and does Omega-3 fatty acids a therapeutic treatment for co-morbidity associated with obstructive sleep apnea.

Preliminary evidence that obese patients with obstructive sleep apnea/hypopnea syndrome are refractory to the acute beneficial metabolic effects of a very low calorie diet

Since obesity seems to play a causal role in both obstructive sleep apnea/hypopnea syndrome (OSAHS) and type 2 diabetes, the question arises whether diet-induced weight loss is equally efficacious in type 2 diabetic patients with and without OSAHS. The present study was aimed to investigate the effect of 1 week very low calorie diet (VLCD) on oxygen desaturation index (ODI) and on glucose regulation in OSAHS versus non-OSAHS patients. Fourteen patients with type 2 diabetes mellitus and morbid obesity were enrolled. According to ODI, patients were divided into 2 groups (with and without OSAHS) and evaluated by a hyperglycemic clamp study, before and after a 7 day-VLCD. After a VLCD, a significant reduction of anthropometric parameters, in the overall group and in subgroups, was observed. M-value and acute insulin response increased significantly only in patients without obstructive sleep apnea (990.10 ± 170.19 vs. 1,205.22 ± 145.73 μmol min(-1) m(-2), p = 0.046; -1.05 ± 8.40 vs. 48.26 ± 11. 90 pmol/L, p = 0.028, respectively). The average 24-h heart rate (24-h HR) fell significantly (p = 0.05), primarily because of a decrease during daytime (p = 0.041), in the whole group. In conclusion, we observed that morbidly obese patients with type 2 diabetes and OSAHS are specifically resistant to the acute beneficial effects of VLCD on metabolic parameters. Our preliminary observation deserves further investigation to clarify the pathogenetic mechanisms involved.

Effect of a very low energy diet on moderate and severe obstructive sleep apnoea in obese men: a randomised controlled trial

OBJECTIVE

To assess the effect of weight loss induced by a very low energy diet on moderate and severe obstructive sleep apnoea in obese men. Design Single centre, two arm, parallel, randomised, controlled, open label trial. Blocked randomisation procedure used for treatment allocation. Setting Outpatient obesity clinic in a university hospital in Stockholm, Sweden. Participants 63 obese men (body mass index 30-40, age 30-65 years) with moderate to severe obstructive sleep apnoea (apnoea-hypopnoea index (AHI) >or=15), treated with continuous positive airway pressure.

INTERVENTIONS

The intervention group received a liquid very low energy diet (2.3 MJ/day) for seven weeks to promote weight loss, followed by two weeks of gradual introduction of normal food, reaching 6.3 MJ/day at week 9. The control group adhered to their usual diet during the nine weeks of follow-up.

MAIN OUTCOME MEASURE

AHI, the major disease severity index for obstructive sleep apnoea. Data from all randomised patients were included in an intention to treat analysis (baseline carried forward for missing data). Results Of the 63 eligible patients, 30 were randomised to intervention and 33 to control. Two patients in the control group were dissatisfied with allocation and immediately discontinued. All other patients completed the trial. Both groups had a mean AHI of 37 events/h (SD 15) at baseline. At week 9, the intervention group's mean body weight was 20 kg (95% confidence interval 18 to 21) lower than that of the control group, while its mean AHI was 23 events/h (15 to 30) lower. In the intervention group, five of 30 (17%) were disease free after the energy restricted diet (AHI <5), with 15 of 30 (50%) having mild disease (AHI 5-14.9), whereas the AHI of all patients in the control group except one remained at 15 or higher. In a subgroup analysis of the intervention group, baseline AHI significantly modified the effectiveness of treatment, with a greater improvement in AHI in patients with severe obstructive sleep apnoea (AHI >30) at baseline compared with those with moderate (AHI 15-30) sleep apnoea (AHI -38 v -12, P<0.001), despite similar weight loss (-19.2 v -18.2 kg, P=0.55). Conclusion Treatment with a low energy diet improved obstructive sleep apnoea in obese men, with the greatest effect in patients with severe disease. Long term treatment studies are needed to validate weight loss as a primary treatment strategy for obstructive sleep apnoea.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN70090382.

Antioxidant nutrient intake and supplements as potential moderators of cognitive decline and cardiovascular disease in obstructive sleep apnea

Cognitive deficits and cardiovascular disease (CVD) are comorbid conditions frequently associated with obstructive sleep apnea (OSA). Oxygen free radical release and its differential regulation of cytokine synthesis and immune modulation resulting from OSA-related hypoxic events have been hypothesized as the underlying mechanism(s) for the cognitive deficits and CVD in OSA. A number of studies have suggested that increased levels of oxidative stress and/or antioxidant deficiencies may also be risk factors in cognitive decline and CVD. The influence of antioxidant nutrients and supplements, such as Vitamins B6, B12, C, E, folic acid, alpha-lipoic acid and Coenzyme Q(10) on cognitive decline and CVD have been investigated. The influence of antioxidant nutrients or supplements on OSA remains to be investigated. Even if dietary or supplemental antioxidants do not prove to be effective therapies for OSA, dietary assessment and prescription to increase dietary intake of neuro- and cardio-protective nutrients may make it possible to reduce some of the cognitive and cardiovascular sequelae associated with OSA.